Mjahoger’s right. I’d take most any FREEZE-capable algorithm from some minimal DECAY time to INF. I’ll add this: I would bind an Aux switch to the Expression Pedal mapping, for the momentary switch action you want. If you’re not using the H9 port for anything else [EXP PED, pedal + 1 switch, or triple AUX switches], I’ve gotten excellent results from using an actual (M Audio) sustain pedal. Great feel; just like a keyboard.
As for a preset, here’s a general idea of how you’d do it in the HALL algorithm. In the 2nd image (linked below), map the expression pedal to INF, rather than FREEZE. Bind an Aux switch to EXP PED, and you’ll “layer” on your notes until you release the sustain pedal / switch. Here’s that HALL preset link:
https://www.eventideaudio.com/comment/34691#comment-34691
I know what you mean about the SuperEgo. Some kind of mixture of the MOMENT & AUTO modes come closest to what (I believe) you want. AUTO … you have to latch & unlatch, but it will overlay notes. MOMENT is more like a FREEZE (single capture) mode. I’ve got several H9s, EHX Freeze and SuperEgo here, so feel free to expand on any more questions you might have. Each unit has its advantages, and some disadvantages.
